diff --git a/src/hashing/cuckoo.cpp b/src/hashing/cuckoo.cpp
index dc5505d..7b4e675 100644
--- a/src/hashing/cuckoo.cpp
+++ b/src/hashing/cuckoo.cpp
@@ -155,6 +155,7 @@ void *gen_cuckoo_entries(void *ctx_void) {
 	for(i = ctx->startpos; i < ctx->endpos; i++, eleptr+=inbytelen) {
 		gen_cuckoo_entry(eleptr, ctx->cuckoo_entries + i, hs, i);
 	}
+	return NULL;
 }
 
 
diff --git a/src/hashing/simple_hashing.cpp b/src/hashing/simple_hashing.cpp
index 55ce6c6..8bfa1ce 100644
--- a/src/hashing/simple_hashing.cpp
+++ b/src/hashing/simple_hashing.cpp
@@ -112,6 +112,7 @@ void *gen_entries(void *ctx_tmp) {
 	}
 	free(tmpbuf);
 	free(address);
+	return NULL;
 }
 
 inline void insert_element(sht_ctx* table, uint8_t* element, uint32_t* address, uint8_t* tmpbuf, hs_t* hs) {
diff --git a/src/ot-based/ot-psi.cpp b/src/ot-based/ot-psi.cpp
index d884d8d..112951e 100644
--- a/src/ot-based/ot-psi.cpp
+++ b/src/ot-based/ot-psi.cpp
@@ -587,6 +587,7 @@ void *otpsi_query_hash_table(void* ctx_tmp) {//GHashTable *map, uint8_t* element
 
 	free(matches);
 	//return size_intersect;
+	return NULL;
 }
 
 //TODO if this works correctly, combine with other find intersection methods and outsource to hashing_util.h
@@ -717,6 +718,7 @@ void print_bin_content(uint8_t* hash_table, uint32_t nbins, uint32_t elebytelen,
 void *receive_masks(void *ctx_tmp) {
 	mask_rcv_ctx* ctx = (mask_rcv_ctx*) ctx_tmp;
 	ctx->sock->Receive(ctx->rcv_buf, ctx->maskbytelen * ctx->nmasks);
+	return NULL;
 }
 
 uint32_t get_stash_size(uint32_t neles) {
diff --git a/src/util/cbitvector.h b/src/util/cbitvector.h
index e47b2ed..c482962 100644
--- a/src/util/cbitvector.h
+++ b/src/util/cbitvector.h
@@ -17,6 +17,8 @@
 
 #define DEFAULT_BITSIZE 128
 
+typedef int BOOL;  // as in Miracl
+
 static const uint8_t REVERSE_NIBBLE_ORDER[16] =
 	{0x0, 0x8, 0x4, 0xC, 0x2, 0xA, 0x6, 0xE, 0x1, 0x9, 0x5, 0xD, 0x3, 0xB, 0x7, 0xF};
 
diff --git a/src/util/crypto/ecc-pk-crypto.cpp b/src/util/crypto/ecc-pk-crypto.cpp
index 4ea7f12..c63b4eb 100644
--- a/src/util/crypto/ecc-pk-crypto.cpp
+++ b/src/util/crypto/ecc-pk-crypto.cpp
@@ -7,6 +7,10 @@
 
 #include "ecc-pk-crypto.h"
 
+#include "../../externals/miracl_lib/ecn.h"
+#include "../../externals/miracl_lib/big.h"
+#include "../../externals/miracl_lib/ec2.h"
+
 
 char *ecx163 = (char *) "2fe13c0537bbc11acaa07d793de4e6d5e5c94eee8";
 char *ecy163 = (char *) "289070fb05d38ff58321f2e800536d538ccdaa3d9";
@@ -203,6 +207,13 @@ void ecc_fe::sample_fe_from_bytes(uint8_t* buf, uint32_t bytelen) {
 }
 
 
+void ecc_fe::print() {
+	cout << (*val) << endl;
+}
+
+void ecc_fe::init() {
+	val = new EC2();
+}
 
 
 ecc_num::ecc_num(ecc_field* fld) {
@@ -245,20 +256,34 @@ void ecc_num::export_to_bytes(uint8_t* buf, uint32_t field_size_bytes) {
 	big_to_bytes ((int32_t) field_size_bytes, val->getbig(), (char*) buf, true);
 }
 
+void ecc_num::print() {
+	cout << (*val) << endl;
+}
+
 
 
 // ecc_brickexp methods
+struct ecc_brickexp::ecc_brickexp_impl {
+	ebrick2 br;
+};
+
 ecc_brickexp::ecc_brickexp(fe* point, ecc_fparams* fparams) {
 	Big x, y;
 	fe2ec2(point)->getxy(x, y);
-	ebrick2_init(&br, x.getbig(), y.getbig(), fparams->BA->getbig(), fparams->BB->getbig(),
-			fparams->m, fparams->a, fparams->b, fparams->c, 8, fparams->secparam);
+	impl = std::make_unique<ecc_brickexp_impl>();
+	ebrick2_init(&impl->br, x.getbig(), y.getbig(), fparams->BA->getbig(),
+			fparams->BB->getbig(), fparams->m, fparams->a, fparams->b,
+			fparams->c, 8, fparams->secparam);
+}
+
+ecc_brickexp::~ecc_brickexp() {
+	ebrick2_end(&impl->br);
 }
 
 void ecc_brickexp::pow(fe* result, num* e)
 {
 	Big xtmp, ytmp;
-	mul2_brick(&br, num2Big(e)->getbig(), xtmp.getbig(), ytmp.getbig());
+	mul2_brick(&impl->br, num2Big(e)->getbig(), xtmp.getbig(), ytmp.getbig());
 	*fe2ec2(result) = EC2(xtmp, ytmp);
 }
 
diff --git a/src/util/crypto/ecc-pk-crypto.h b/src/util/crypto/ecc-pk-crypto.h
index 8c72bce..26fec4d 100644
--- a/src/util/crypto/ecc-pk-crypto.h
+++ b/src/util/crypto/ecc-pk-crypto.h
@@ -9,10 +9,11 @@
 #define ECC_PK_CRYPTO_H_
 
 #include "pk-crypto.h"
+#include <memory>
 
-#include "../../externals/miracl_lib/ecn.h"
-#include "../../externals/miracl_lib/big.h"
-#include "../../externals/miracl_lib/ec2.h"
+// forward declarations
+class Big;
+class EC2;
 
 
 #define fe2ec2(fieldele) (((ecc_fe*) (fieldele))->get_val())
@@ -94,7 +95,7 @@ public:
 	void export_to_bytes(uint8_t* buf, uint32_t field_size_bytes);
 	void import_from_bytes(uint8_t* buf, uint32_t field_size_bytes);
 	void set_rnd(uint32_t bits);
-	void print() {cout << (*val) << endl;};
+	void print();
 
 private:
 	Big* val;
@@ -118,11 +119,11 @@ public:
 	void import_from_bytes(uint8_t* buf);
 	void sample_fe_from_bytes(uint8_t* buf, uint32_t bytelen);
 
-	void print() {cout << (*val) << endl;};
+	void print();
 
 
 private:
-	void init() {val = new EC2();};
+	void init();
 	EC2* val;
 	ecc_field* field;
 };
@@ -130,11 +131,12 @@ private:
 class ecc_brickexp : public brickexp {
 public:
 	ecc_brickexp(fe* point, ecc_fparams* fparams);
-	~ecc_brickexp() {ebrick2_end(&br);}
+	~ecc_brickexp();
 
 	void pow(fe* res, num* e);
 private:
-	ebrick2 br;
+	struct ecc_brickexp_impl;	// used to hide MIRACL's ebrick2 type in the implementation
+	std::unique_ptr<ecc_brickexp_impl> impl;
 };
 
 void point_to_byte(uint8_t* pBufIdx, uint32_t field_size_bytes, EC2* to_export);
diff --git a/src/util/crypto/pk-crypto.h b/src/util/crypto/pk-crypto.h
index aa9ce39..999f1bf 100644
--- a/src/util/crypto/pk-crypto.h
+++ b/src/util/crypto/pk-crypto.h
@@ -18,7 +18,7 @@ class brickexp;
 class pk_crypto {
 public:
 	pk_crypto(seclvl sp, uint8_t* seed){};
-	~pk_crypto(){};
+	virtual ~pk_crypto(){};
 	virtual num* get_num() = 0;
 	virtual num* get_rnd_num(uint32_t bitlen=0) = 0;
 	virtual fe* get_fe() = 0;
@@ -45,7 +45,7 @@ protected:
 class num {
 public:
 	num(){};
-	~num(){};
+	virtual ~num(){};
 	virtual void set(num* src) = 0;
 	virtual void set_si(int32_t src) = 0;
 	virtual void set_add(num* a, num* b) = 0;
@@ -60,7 +60,7 @@ public:
 class fe {
 public:
 	fe(){};
-	~fe(){};
+	virtual ~fe(){};
 	virtual void set(fe* src) = 0;
 	virtual void set_mul(fe* a, fe* b) = 0;
 	virtual void set_pow(fe* b, num* e) = 0;
@@ -78,7 +78,7 @@ protected:
 class brickexp {
 public:
 	brickexp(){};
-	~brickexp(){};
+	virtual ~brickexp(){};
 
 	virtual void pow(fe* result, num* e) = 0;
 };
diff --git a/src/util/ot/baseOT.h b/src/util/ot/baseOT.h
index 64262a1..0fce20e 100644
--- a/src/util/ot/baseOT.h
+++ b/src/util/ot/baseOT.h
@@ -23,7 +23,7 @@ class BaseOT
 {
 	public:
 		BaseOT(crypto* crypt, field_type ftype){m_cCrypto = crypt; m_cPKCrypto = crypt->gen_field(ftype); };
-		~BaseOT(){delete m_cPKCrypto; };
+		virtual ~BaseOT(){delete m_cPKCrypto; };
 
 		virtual void Sender(uint32_t nSndVals, uint32_t nOTs, CSocket* sock, uint8_t* ret) = 0;
 		virtual void Receiver(uint32_t nSndVals, uint32_t uint32_t, CBitVector& choices, CSocket* sock, uint8_t* ret) = 0;
diff --git a/src/util/ot/kk-ot-extension.cpp b/src/util/ot/kk-ot-extension.cpp
index 69f7ca5..9f8390a 100644
--- a/src/util/ot/kk-ot-extension.cpp
+++ b/src/util/ot/kk-ot-extension.cpp
@@ -1,5 +1,7 @@
 #include "kk-ot-extension.h"
 
+#define TRUE 1  // as in Miracl
+
 /*
  * ---------------------------------- OT Extension Sender Part --------------------------------------
  */
diff --git a/src/util/ot/naor-pinkas.cpp b/src/util/ot/naor-pinkas.cpp
index 380811f..1bdfb51 100644
--- a/src/util/ot/naor-pinkas.cpp
+++ b/src/util/ot/naor-pinkas.cpp
@@ -81,7 +81,7 @@ void NaorPinkas::Receiver(uint32_t nSndVals, uint32_t nOTs, CBitVector& choices,
 	delete bc;//BrickDelete(&bc);
 	delete bg;//BrickDelete(&bg);
 
-	delete [] pBuf;
+	free(pBuf);
 	free(PK_sigma);
 	free(pDec);
 	free(pC);